The present invention is novel organofunctional polysiloxane and organofunctional cyclosiloxane compositions and a process for their preparation. The process for preparation of these siloxane compositions comprises contacting a mixture containing a cyclo(organohydrogen)-siloxane or a poly(organohydrogen)siloxane, a mono-.alpha.-olefin, an alpha,omega-triene, and a triorganosilyl source, with a platinum catalyst, at a temperature within a range of 50.degree. C. to 200.degree. C. The products of this process are organofunctional polysiloxanes and organofunctional cyclosiloxanes.
The reaction of olefins with SiH-containing compounds is well known. For example, Wagner et al., U S. Pat. No. 2,851,473, issued Sep. 9, 1958. describe the use of platinum deposited on the gamma allotrope of alumina to catalyze the reaction between molecules containing C=C bonds and SiH containing monomers.
British Patent No. 1,104,206, published Feb. 21, 1968, describes a process where a silicon compound containing at least one silicon-bonded hydrogen atom per molecule and not more than two hydrogen atoms attached to any one silicon atom is reacted with a compound containing aliphatically unsaturated carbon atoms in the presence of a platinum complex. Specific examples of compounds containing aliphatically unsaturated carbon atoms include compounds containing one and two unsaturated bonds.
German Patent Application No. P-2,166.867.7, published Apr. 22, 1976, describes a process where the reaction of trichlorosilane or methyldichlorosilane with a triene is catalyzed with platinum compounds to form bis-silyl olefins. The bis-silyl olefins are further reacted with polymeric unsaturated hydrocarbon chains in the presence of a Lewis acid and a metathesis catalyst to form polymeric hydrocarbons with reactive silyl terminal groups.
Brennan, U.S. Pat. No. 3,440,263, issued Apr. 22, 1969, describes a process in which olefinic compounds containing a least one ethylenic bond is reacted with a siloxane polymer containing SiH bonds to form alkylated siloxanes. Platinum or platinum compounds supported on charcoal were reported as a suitable catalyst for the process.
Getson. U.S. Pat. No. 4,166,078, issued Aug. 28, 1979, describes a process where a modified organopolysiloxane composition containing in situ generated particulate matter is prepared by reacting an organohydrogenpolysiloxane with monomers containing aliphatic unsaturation in the presence of free radical initiators. Getson further describes a process where the modified organopolysiloxane composition is reacted with a compound having at least two vinyl groups per molecule as a cross-linking agent and a catalyst which promotes the addition of SiH groups present in the modified organopolysiloxane composition to vinyl groups of the cross-linking agent. Platinum is described as a suitable catalyst for the cross-linking process.
The object of the present invention is to provide a process for the production of organofunctional siloxane compositions with enhanced compatibility with organic compositions. The substitution of mono-.alpha.-olefin for hydrogen on the silicon atoms of the siloxane can be used to control the organic compatibility of the siloxane while the substitution of alpha,omega-trienes (.alpha.,.OMEGA.-triene) for hydrogen on the silicon atoms of the siloxane can be used to cross-link the siloxanes. The internal unsaturated bond of the .alpha.,.OMEGA.-triene is not effected by the platinum catalyst and thus remains intact imparting an organofunctionality to the siloxane compositions. The cross-linking of the siloxane compositions is further controlled by the addition of a triorganosilyl source, which can add across terminal unsaturated bonds of the .alpha.,.OMEGA.-trienes. This allows for the level of cross-linking of the siloxane polymers to be varied while maintaining a constant level of organofunctionality.